Incidence of Chlamydophila Pneumoniae Infection in Children During 2007–2010

Abstract

Chlamydophila pneumoniae is the etiological agent of pharyngitis, bronchitis, and pneumonia. The aim of the study was to evaluate the frequency of chlamydial respiratory infections in children in the Lower Silesia Region in Poland in 2007–2010. There were 2,733 throat swabs examined, obtained from hospitalized patients aged from 20 months to 18 years with various clinical symptoms such as dry cough, productive cough, and from asymptomatic ambulatory patients. An indirect immunofluorescence technique, based on monoclonal antibodies labeled with fluorescein isothiocyanate, was used for detection of Chl. pneumoniae antigen. Overall, there were 1,114, 503, 641, and 475 patients studied in the consecutive 2007, 2008, 2009, and 2010 years. There clearly were fewer patients each next year submitted for Chl. pneumoniae detection procedure, which stemmed from the declining severity of respiratory infections noted in children and thus less demanding diagnostic workup commissioned by physicians. The percentage of results positive for Chl. pneumoniae antigen amounted to 53.3, 41.6, 43.1, and 36.4 % in the consecutive years, respectively. Detection of chlamydial infections had thus a decreasing tendency in the period studied. There also were decreases in Chl. pneumoniae detection rate in cases stratified due to the presenting symptom: dry cough, productive cough, or in asymptomatic cases. A milder course of respiratory infections resulting in a decreased number of children examined for Chl. pneumoniae antigen in consecutive years, makes it difficult to draw definite conclusions on the factual incidence rate. Nevertheless, we believe we have shown, from the clinical standpoint, a dropping rate of Chl. pneumoniae detection in children with respiratory infections.